During World War II, U.S. Coast Artillerymen (serving the huge coastal artillery batteries) were known as "Cosmoliners" because they were tasked with the near constant cosmoline application ("greasing down") of the guns. The chemical was also used to coat weapons (including entire tanks) for long sea voyages, as it prevented rust even in salty conditions.

Aren't they 40 feet deep? if so, that is double the pressure at sea level. As much as I want to see three times as much cosmoline as there was Spitfire and some intact aircraft, I can't say my gut feels that way. All it takes is a data plate and money and you can restore any airplane. Oh, I forgot. Lots and lots of money.